i fixed some test codes.

aecpic.py

@@ -18,16 +18,6 @@ import pillow_avif
 import argparse
 from magika import Magika
 
-
-if 'ANVIL_API_PORT' not in os.environ:
-    print('not in Anvil.')
-    sys.exit(1)
-
-host = 'localhost'
-ANVIL_API_PORT = os.environ['ANVIL_API_PORT']
-ANVIL_API_SESS = os.environ['ANVIL_API_SESS']
-ANVIL_WIN_ID = os.environ['ANVIL_WIN_ID']
-
 def getSuffix(byts):
     '''
     get the filetype in the byts, and change sufifix
@@ -56,8 +46,8 @@ def download(url):
     download the iamge file to the temporary file.
 
     >>> import aecpic
-    >>> n, t = aecpic.download('https://moli-green.xyz/img.webp')
-    >>> assert n != None and t == 'webp'
+    >>> r = aecpic.download('https://moli-green.xyz/img.webp')
+    >>> assert r != ''
     '''
 
     cr = subprocess.run(['curl', url], capture_output = True)
@@ -79,11 +69,11 @@ def getPNG(url):
     '''
     Download the file from the URL, convert and save to PNG format.
 
-    >>> import apcpic
-    >>> r = apcpic.getPNG('https://moli-green.xyz/img.webp')
-    >>> if r != '':
-    ...     pass
+    >>> import aecpic
+    >>> r = aecpic.getPNG('https://moli-green.xyz/img.webp')
+    >>> assert r != ''
     '''
+
     png_filename = ''
     with tempfile.NamedTemporaryFile(
             mode='wb',
@@ -96,12 +86,14 @@ def getPNG(url):
     img.save(png_filename)
     return png_filename
 
-def get_anvil_window():
+def get_anvil_window(host='localhost'):
     '''
     Get or create Anvil's window.
     '''
 
-    global ANVIL_WIN_ID
+    ANVIL_API_PORT = os.environ['ANVIL_API_PORT']
+    ANVIL_API_SESS = os.environ['ANVIL_API_SESS']
+    ANVIL_WIN_ID = os.environ['ANVIL_WIN_ID']
 
     if ANVIL_WIN_ID != '':
         return ANVIL_WIN_ID
@@ -131,7 +123,9 @@ def anvil_Pic(host='localhost', url=None):
 
     filename = getPNG(url)
 
-    anvil_win_id = get_anvil_window()
+    ANVIL_API_PORT = os.environ['ANVIL_API_PORT']
+    ANVIL_API_SESS = os.environ['ANVIL_API_SESS']
+    ANVIL_WIN_ID = get_anvil_window()
 
     h = {
         'Anvil-Sess': ANVIL_API_SESS,
@@ -158,5 +152,10 @@ if __name__ == '__main__':
     p.add_argument('url', help='Image URL')
     arg = p.parse_args()
     host = arg.host
+
+    if 'ANVIL_API_PORT' not in os.environ:
+        print('not in Anvil.')
+        sys.exit(1)
+    
     anvil_Pic(host, arg.url)